Dissemination of the blaKPC gene by clonal spread and horizontal gene transfer: comparative study of incidence and molecular mechanisms
Dissemination of the blaKPC gene by clonal spread and horizontal gene transfer: comparative study of incidence and molecular mechanisms
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DOI：
10.1093/jac/dkw106
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发表时间：
2016-08-01
影响因子：
5.2
通讯作者：
Carmeli, Yehuda
中科院分区：
文献类型：
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作者：
Adler, Amos;Khabra, Efrat;Carmeli, Yehuda
除了产KPC肺炎克雷伯菌克隆复合体(CC)-258克隆的全球传播外，blA(KPC)基因也可能通过水平基因转移(HGT)传播，当在一个患者体内分离到多个产KPC的肠杆菌科(KPC-Ent)物种时，可能会被怀疑。我们的目的是描述单独分离的KPC-KP(单独的KPC-KP)与与另一个KPC-Ent物种一起分离的KPC-KP(联合KPC-KP)的发病率和分子特征。分离株于2011年4月至2012年8月在拉尼亚多医学中心收集。分型采用CC-258多重聚合酶链式反应和多重聚合酶链式反应。用质粒MLST(PMLST)鉴定。通过测序对bla(Kpc)基因的遗传环境进行了研究，在17个月的时间里，有281例单一kpc-kp和8例联合kpc(PaEuroS<；aEuroS0.0001)。在关节KPC-KP患者中，增加的KPC-Ent种是大肠埃希菌(NAEuroS=aEuroS6)、产气肠杆菌(NAEuroS=aEuroS1)、阴沟肠杆菌(NAEuroS=aEuroS1)和弗劳地柠檬酸杆菌(NaEuroS=aEuroS1)。所有的KPC-KP分离株(NaEuroS=aEuroS27)都属于CC-258克隆，并携带Bla(KPC-3)等位基因，位于Tn4401a转座子内。相反，KPC-KP/KPC-Ent联合分离株属于不同的STS，除一株外，其余均携带blA(KPC-2)等位基因。Bla(kpc-2)基因位于IncN/pMLST-15型质粒携带的Delta Tn4401c转座子内，具有较高的接合效率。本研究重点介绍了bla(Kpc)基因的两种传播模式：CC-258克隆的克隆性传播和HGT相关的传播，由穿梭于不同物种和克隆之间的ST-15质粒介导。
In addition to the global spread of the KPC-producing Klebsiella pneumoniae (KPC-KP) clonal complex (CC)-258 clone, the bla(KPC) gene may also spread by horizontal gene transfer (HGT), as suspected when more than one KPC-producing Enterobacteriaceae (KPC-Ent) species are isolated in a single patient. We aimed to characterize the incidence and molecular features of KPC-KP that were isolated alone (singular KPC-KP) versus KPC-KP that were isolated together with another KPC-Ent species (joint KPC-KP).Isolates were collected from April 2011 to August 2012 at the Laniado Medical Center. Typing was done by CC-258 multiplex PCR and MLST. Plasmids were characterized by plasmid MLST (pMLST). The genetic environment of the bla(KPC) gene was studied by sequencing.During the 17 month period, there were 281 cases of singular KPC-KP and 8 cases of joint KPC-KP (PaEuroS < aEuroS0.0001). Among the patients with joint KPC-KP, the additional KPC-Ent species were Escherichia coli (naEuroS=aEuroS6), Enterobacter aerogenes (naEuroS=aEuroS1), Enterobacter cloacae (naEuroS=aEuroS1) and Citrobacter freundii (naEuroS=aEuroS1). All singular KPC-KP isolates tested (naEuroS=aEuroS27) belonged to the CC-258 clone and carried the bla(KPC-3) allele, located inside a Tn4401a transposon. In contrast, joint KPC-KP/KPC-Ent isolates belonged to different STs and all but one carried the bla(KPC-2) allele. The bla(KPC-2) gene was located inside Delta Tn4401c transposons that were harboured by IncN/pMLST ST-15-type plasmids possessing high conjugation efficiency.This study highlights two dissemination modes of the bla(KPC) gene: clonal spread of the CC-258 clone and, far less commonly, HGT-related spread, mediated by ST-15 plasmids that shuttle between a variety of species and clones.